diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index d362f203f39a671afef66b7898b7bd939dc397d3..2742f60f91d0b3bfacd0380aad1f05b7ea8b113f 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,14 @@
+2005-01-26  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/ext/mt_allocator.h
+	(struct __per_type_pool_policy<,, false>::_S_get_pool,
+	struct __per_type_pool_policy<,, true>::_S_get_pool): Scale
+	_M_chunk_size too with sizeof(_Tp), otherwise the allocator
+	breaks down as soon as sizeof(_Tp) >~ _S_chunk_size / 128;
+	reduce to 64 the multiplier for _M_max_bytes (safer wrt
+	_Binmap_type being a short); trivial reformattings.
+	* testsuite/ext/mt_allocator/check_allocate_big_per_type.cc: New.
+
 2005-01-26  Paolo Carlini  <pcarlini@suse.de>
 
 	* acinclude.m4 ([GLIBCXX_ENABLE_C99]): Add ac_c99_complex
diff --git a/libstdc++-v3/include/ext/mt_allocator.h b/libstdc++-v3/include/ext/mt_allocator.h
index 72fd181322fa85e0f19a99199fb7fec066b24b3c..de1656320a1b2f9599b87edce0aa363c5c6da3b8 100644
--- a/libstdc++-v3/include/ext/mt_allocator.h
+++ b/libstdc++-v3/include/ext/mt_allocator.h
@@ -1,6 +1,6 @@
 // MT-optimized allocator -*- C++ -*-
 
-// Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+// Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -494,14 +494,25 @@ namespace __gnu_cxx
       _S_get_pool()
       { 
 	// Sane defaults for the _PoolTp.
-	const static size_t __align = __alignof__(_Tp) >= sizeof(typename pool_type::_Block_record) ? __alignof__(_Tp) : sizeof(typename pool_type::_Block_record);
-	static __pool_base::_Tune _S_tune(__align, sizeof(_Tp) * 128, (sizeof(_Tp) * 2) >= __align ? sizeof(_Tp) * 2 : __align, __pool_base::_Tune::_S_chunk_size, __pool_base::_Tune::_S_max_threads, __pool_base::_Tune::_S_freelist_headroom, getenv("GLIBCXX_FORCE_NEW") ? true : false);
+	typedef typename pool_type::_Block_record _Block_record;
+	const static size_t __align = (__alignof__(_Tp) >= sizeof(_Block_record)
+				       ? __alignof__(_Tp)
+				       : sizeof(_Block_record));
+
+	typedef typename __pool_base::_Tune _Tune;
+	static _Tune _S_tune(__align, sizeof(_Tp) * 64,
+			     sizeof(_Tp) * 2 >= __align ? sizeof(_Tp) * 2
+			                                : __align,
+			     sizeof(_Tp) * _Tune::_S_chunk_size,
+			     _Tune::_S_max_threads,
+			     _Tune::_S_freelist_headroom,
+			     getenv("GLIBCXX_FORCE_NEW") ? true : false);
 	static pool_type _S_pool(_S_tune);
 	return _S_pool;
       }
 
       static void
-      _S_initialize_once() 
+      _S_initialize_once()
       { 
 	static bool __init;
 	if (__builtin_expect(__init == false, false))
@@ -529,14 +540,25 @@ namespace __gnu_cxx
       _S_get_pool()
       { 
 	// Sane defaults for the _PoolTp.
-	const static size_t __align = __alignof__(_Tp) >= sizeof(typename pool_type::_Block_record) ? __alignof__(_Tp) : sizeof(typename pool_type::_Block_record);
-	static __pool_base::_Tune _S_tune(__align, sizeof(_Tp) * 128, (sizeof(_Tp) * 2) >= __align ? sizeof(_Tp) * 2 : __align, __pool_base::_Tune::_S_chunk_size, __pool_base::_Tune::_S_max_threads, __pool_base::_Tune::_S_freelist_headroom, getenv("GLIBCXX_FORCE_NEW") ? true : false);
+	typedef typename pool_type::_Block_record _Block_record;
+	const static size_t __align = (__alignof__(_Tp) >= sizeof(_Block_record)
+				       ? __alignof__(_Tp)
+				       : sizeof(_Block_record));
+
+	typedef typename __pool_base::_Tune _Tune;
+	static _Tune _S_tune(__align, sizeof(_Tp) * 64,
+			     sizeof(_Tp) * 2 >= __align ? sizeof(_Tp) * 2
+                                                        : __align,
+			     sizeof(_Tp) * _Tune::_S_chunk_size,
+			     _Tune::_S_max_threads,
+			     _Tune::_S_freelist_headroom,
+			     getenv("GLIBCXX_FORCE_NEW") ? true : false);
 	static pool_type _S_pool(_S_tune);
 	return _S_pool;
       }
 
       static void
-      _S_initialize_once() 
+      _S_initialize_once()
       { 
 	static bool __init;
 	if (__builtin_expect(__init == false, false))
diff --git a/libstdc++-v3/testsuite/ext/mt_allocator/check_allocate_big_per_type.cc b/libstdc++-v3/testsuite/ext/mt_allocator/check_allocate_big_per_type.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2d3b5b14dbe33c82f76fa91d7717f7eeae2f098f
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/mt_allocator/check_allocate_big_per_type.cc
@@ -0,0 +1,55 @@
+// 2005-01-26  Paolo Carlini  <pcarlini@suse.de>
+//
+// Copyright (C) 2005 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+#include <memory>
+#include <ext/mt_allocator.h>
+#include <cstring>
+#include <testsuite_hooks.h>
+
+struct big { char array[256]; };
+
+// __per_type_pool_policy
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  typedef big value_type;
+
+  using __gnu_cxx::__pool;
+  using __gnu_cxx::__per_type_pool_policy;
+
+#ifdef __GTHREADS
+  typedef __per_type_pool_policy<value_type, __pool, true> policy_type;
+#else
+  typedef __per_type_pool_policy<value_type, __pool, false> policy_type;
+#endif
+  typedef __gnu_cxx::__mt_alloc<value_type, policy_type> allocator_type;
+
+  allocator_type a;
+  allocator_type::pointer p1 = a.allocate(64);
+  std::memset((void*)p1, 0, sizeof(big) * 64);
+  a.deallocate(p1, 64);
+}
+
+int main()
+{
+  test01();
+  return 0;
+}